The winner gets: Most votes advances to the Sweet Sixteen (round of 16), and a shot at the Biofuels Elite Eight.

The loser: Goes home.

Laurels: Codexis is the 9th ranked company in the 2010-11 50 Hottest Companies in Bioenergy poll. Rentech is currently #25.

The match-up: It’s Fermentation vs Fischer-Tropsch. Codexis took 66 percent of the votes in its first round battle with Propel Fuels. Rentech prevailed over BlueFire Renewables 57-43.

Codexis is producing enzymes for Shell for low-cost cellulosic biofuels, and producing low-cost renewable chemicals for itself. Codexis is increasingly aimed at sugarcane bagasse as a breakout feedstock available at scale, through the Shell-Cosan “Raizen” joint venture.

Rentech is commercializing a Fischer-Tropsch fuels and chemicals system that it will demonstrate in the next year and commercialize in Canada among other locations.